Elements of the Taliban are open to talks with the Afghan government, US Defense Secretary Jim Mattis said Tuesday, a potentially significant move that runs counter to the insurgents' long-term refusal to talk to Kabul. Mattis flew into the war-torn nation on an unannounced visit two weeks after Afghan President Ashraf Ghani unveiled a plan to open peace talks with the Taliban, Afghanistan's biggest militant group. The Taliban have so far given no formal response to Kabul's offer for negotiations, but have published a lengthy statement and an online commentary that analysts say are an oblique rejection of the proposal.